Approach to a cough (pediatrics): Clinical sciences

A cough is a protective airway reflex that clears the airway of mucus or other irritants. This reflex is a common feature of conditions affecting the upper and lower airway, such as infection, inflammation, or airway obstruction. Depending on its duration, you can classify cough in pediatric patients as acute, chronic, or episodic.

Now, if a pediatric patient presents with a cough, first perform an ABCDE assessment to determine if your patient is stable or unstable.

If unstable, stabilize their airway, breathing, and circulation, and consider intubation for apnea or shallow, ineffective respirations. Next, obtain IV access and put your patient on continuous vital sign monitoring, including blood pressure, heart rate, respiratory rate, and pulse oximetry. Finally, provide supplemental oxygen, if needed.

Let’s move on to stable patients

When it comes to stable patients, obtain a focused history and physical examination. History usually reveals a cough, possibly with wheezing and dyspnea. On physical exam, you might notice signs indicating increased work of breathing, like tachypnea, nasal flaring, or retractions. Additionally, you may hear wheezing, stertor, or stridor. Your next step is to assess the cough’s duration.

First, let’s look at patients with an acute cough, meaning it started no more than 2 weeks ago.

Here, assess the onset of the cough. If it began abruptly, consider foreign body aspiration. Caregivers may have witnessed a choking event, and physical exam could reveal localized wheezing, unilateral absence of breath sounds, and possibly stridor.

Next, get a neck and chest X-ray, which might reveal a foreign body. However, since a lot of them are radiolucent, you should look for indirect signs like atelectasis or air trapping. If you see any of these, diagnose foreign body aspiration.

Here’s a clinical pearl! The abrupt onset of cough, stridor, and wheezing can also be seen in anaphylaxis. You can differentiate anaphylaxis from foreign body aspiration based on history and exam findings.

Anaphylaxis can occur at any age and is associated with urticaria, facial swelling, bilateral wheezing, and shock. On the flip side, foreign body aspiration is most common in older infants and toddlers and typically causes unilateral wheezing without rash or swelling.

Alright, let’s discuss acute cough with a gradual onset. In this case, consider infection. First up is upper respiratory infection, or URI for short.

These patients report rhinorrhea; a cough that might be productive; and occasionally, fever, headache, or body aches. Physical exam usually demonstrates nasal congestion, enlarged nasal turbinates, and possibly facial and sinus tenderness.

With these findings, diagnose URI which encompasses infections involving the respiratory tract from the nose to the trachea, such as nasopharyngitis, also known as the “common cold”.

Now let’s look at croup, which involves the upper and lower respiratory tract. These patients are generally between 6 months and 3 years of age. Their caregivers usually report low-grade fever and hoarseness, with a barking, seal-like cough that worsens at night.

On physical exam, you might find tachypnea with normal oxygen saturation and possibly inspiratory stridor. Additionally, you may notice signs indicating increased work of breathing, such as suprasternal, intercostal, and subcostal retractions.

With these findings, diagnose croup, also called laryngotracheobronchitis, which is commonly caused by the parainfluenza virus.

Finally, let’s discuss lower respiratory infection. Patients typically report a fever, while physical exam may reveal tachypnea and adventitious breath sounds, like crackles, rhonchi, or wheezing. Your patient may also have a decreased oxygen saturation. With these findings, diagnose lower respiratory infection, which includes bronchiolitis and pneumonia.

Here’s another clinical pearl! You don’t always need imaging to diagnose a lower respiratory infection, but if the diagnosis is unclear, order an X-ray. The presence of hyperinflation suggests bronchiolitis, while lobar consolidation suggests bacterial pneumonia, and bilateral patchy infiltrates suggest viral pneumonia.

Let’s switch gears and discuss chronic cough, which lasts more than 4 weeks. Your next step here is to assess the cough’s triggers. If a cough is triggered by positional changes, consider structural airway anomalies or airway compression.

Patients with structural airway anomalies usually present during infancy with a cough that might be accompanied by intermittent cyanotic episodes. Symptoms improve while the patient is lying prone and worsen after bronchodilator use. Physical exam reveals monophonic, central expiratory wheezes and occasionally, biphasic stridor.

In this case, consider an airway anomaly and obtain a bronchoscopy. If you notice abnormal airway structure, diagnose structural airway anomaly. Common examples include tracheomalacia and laryngomalacia, which are structural weaknesses that cause airways to collapse during crying or supine positioning.

As for airway compression, these patients present with dyspnea and cough while lying supine. If the exam reveals lymphadenopathy, consider airway compression from an anterior mediastinal mass; such as thymoma or lymphoma; and obtain a chest X-ray, CT scan, or MRI. A mass in the anterior mediastinum confirms the diagnosis of mediastinal mass.

Alright, let’s switch gears and discuss patients whose cough is triggered by recurrent infections. In this case, consider chronic lung diseases like cystic fibrosis and primary ciliary dyskinesia.

These patients often report a daily cough that’s described as “wet” or “productive”, and many experience poor weight gain. Physical exam reveals nasal polyps, digital clubbing, and occasionally, audible rhonchi.